The present invention relates to a net light set, and more particularly to an economical net light set using only a single active wire.
Net light sets are well-known in the prior art which exemplifies a broad range of different embodiments. Nonetheless, in the United States the manufacture and sale of a net light set is sharply limited by the standards and requirements of the UL (Underwriters Laboratories). Whether or not the UL requirements have the force of law, a failure to obtain the coveted UL certification may sound the death knell of any commercial electrical product. UL requirements involve standards for ultraviolet (UV)-rating (for outdoor use), temperature resistance, flammability (flame resistance), pull weight (tensile strength) and the like. For example, the UL requires that a current-carrying wire be either by itself of a thickness (18 gauge) such that its use would be uneconomical or thinner (22 gauge) and twisted together with another wire such that the twisted wires in tandem support one another. Thus a prior art net light set typically includes a current-carrying active wire and a current-carrying return wire twisted together to form the various columns or icicles of the light set and optionally a bypass wire extending horizontally from one end of the light set to the other end of the light set and being twisted together at various points along its length with adjacent portions of the twisted together active and return wires. While this latter technique for meeting the UL standard is economically superior to the use of the oversized wire, it is not entirely satisfactory from the point of view of the manufacturer as it requires the use of a return wire which is substantially of the same length as the active wire. The conductive core of the insulated wires is a major expense in the production of light sets, while the insulative outer covering is by itself only a small fraction of the production cost.
Accordingly, it is an object of the present invention to provide a UL-acceptable net light set which is economical to manufacture.
Another object is to provide such a set which employs a return wire of substantially lesser length than the active wire.
A further object is to provide such a light set which is simple and inexpensive to manufacture, use and maintain.
The above and related objects of the present invention are obtained in a net light set according to the present invention. The net light set comprises a first common wire means extending in a first direction, the first common wire means including lengths of a bypass wire and a return wire. A plurality of series-connected light strings extend physically parallel to each other and in a second direction transverse to the first direction. Each light string includes a plurality of lamp sockets and a plurality of intermediate lengths of a single active wire connecting the lamp sockets in series. In each of the light strings intermediate the first and last light strings, the single active wire is twisted together intermediate the lamp sockets only with a first non-wire extending in the second direction for enhanced tensile strength. At least one second non-wire extends in the first direction and physically connects intermediate lengths of each light string with corresponding intermediate lengths of other light strings. Plug means are disposed at one end of the light set and include the bypass and return wires.
In a Straight Return embodiment, in the first and last light strings, the single active wire is twisted together only with the first non-wire intermediate the lamp sockets for enhanced tensile strength.
In a U-Return embodiment, the first and last light strings are formed of lengths of the single active wire twisted together with lengths of the return wire for enhanced tensile strength, and a second common wire means extends in the first direction parallel to and spaced from the first common wire means, the second common wire means including lengths of the single active wire and/or lengths of the first non-wire twisted together with a single length of the return wire for enhanced tensile strength. The second common wire means further includes lengths of the first non-wire twisted together with the single active wire and the return wires for enhanced tensile strength.
In an Extra Non-wire embodiment, at least one of the first and second common wire means (and preferably each) includes a length of an additional non-wire extending in the first direction between the first light string and the last light string and twisted together with the wires and non-wires thereof.
In a Sub-Set embodiment, the set is in turn comprised of a plurality of series-connected light sub-sets wired in parallel, each light sub-set (except optionally only the last sub-set) further including a bypass wire twisted together with at least one of the first and second common wire means.
In a Multiple Sets embodiment, a plurality of the light sets are provided, and in each light set (excepting optionally only the last light set) an end connector means is disposed at an opposed end of the light set and the bypass wire establishes electrical communication between the plug means and the end connector of the light set.
Preferably, in all embodiments the first and second non-wires resemble the active wire in outward appearance.
The present invention further encompasses a net light set useable as one of a plurality of interconnected net light sets. Each set comprises, at one end of the set, a plug having a pair of conductors for connection to a power supply or an end connector of another light set, and, at an opposite end of the set, an end element selected from the group consisting of an end connector adapted to receive the plug of another light set and means electrically connecting adjacent free ends of the bypass and return wires. A bypass wire extends across the set in electrical communication with a live one of the conductors, and a return wire extends across the set in electrical communication with a return one of the conductors. A plurality of active wires are provided, each active wire extending across a respective one of the subsets substantially in a plurality of electrically and physically interconnected, horizontally spaced vertical strings and being in electrical and physical communication with the bypass wire at a beginning end of a respective subset and with the return wire at a terminal end of a respective subset. A plurality of lamp sockets are disposed in series in electrical and physical communication and spaced along the active wire of each subset. A first non-electrical pseudowire (e.g., a first non-wire) resembling the active wire in outward appearance is twisted together with the active wire in each subset intermediate the lamp sockets thereof in order to provide additional tensile strength to each vertical string of the subset, and at least one second non-electrical pseudowire (e.g., a second non-wire) resembling the active wire in outward appearance connects horizontally aligned segments of the vertical strings of the set to form a net appearance.
There are either a plurality of vertically spaced apart and linearly extending second pseudowires or a single second pseudowire extending throughout the set in a xe2x80x9cZxe2x80x9d shape pattern. Each of the at least one second pseudowires directly connects horizontally aligned lamp sockets of the vertical strings of the set to form a net appearance or connects horizontally aligned portions of the active wire and the first pseudowire adjacent the lamp sockets.
Each of the bypass wire, the return wire, and the active wire is formed of an electrically conductive metal core and an electrically insulative sheath thereover, and each of the first and second pseudowires is formed of an electrically insulative polymeric sheath without an electrically conductive metal core therein. The first pseudowire exhibits a tensile strength of at least 28 pounds, while the second pseudowire may exhibit a tensile strength of less than 28 pounds.
The return wire and the bypass wire extend essentially directly across the set at a top thereof, or the bypass wire extends essentially directly across the set at a top thereof and the return wire extends in a U-shape configuration along one vertically extending side, a bottom, and another vertically extending side of the set.
In the former Straight Return embodiment, the return wire and the bypass wire extend essentially directly across the set at a top thereof. Within each subset, adjacent pairs of the vertical strings are connected by the first pseudowire and the active wire twisted together. Alternatively, adjacent pairs of the vertical strings are connected together alternately at the top of one adjacent pair of the vertical strings and at the bottom of the next adjacent pair of the vertical strings.
In the latter U-Return embodiment, the first pseudowire is twisted together with the active wire in each vertical string in each subset (excepting optionally a first vertical string of the first subset and a last vertical string of the last subset), the active wire of the first and last vertical strings being twisted together with portions of the return wire extending along the vertically extending sides of the set. Alternately, portions of the active wire extending across at least one pair of adjacent vertical strings at the bottom of a respective one of the subsets and portions of the first pseudowire extending across at least one other pair of adjacent vertical strings at the bottom of a respective one of the subsets are twisted together with respective successive portions of the return wire. The first pseudowire is twisted together with the active wire in each vertical string in each subset. Portions of the active wire extending across at least one pair of adjacent vertical strings at the top of a respective one of the subsets and portions of the first pseudowire extending across at least one pair of adjacent vertical strings at the top of a respective one of the subsets are twisted together with respective portions of the return and bypass wires. In this instance, portions of the active wire extend across at least one pair of adjacent vertical strings at the top of a respective one of the subsets and portions of the first pseudowire extend across at least one adjacent pair of adjacent vertical strings at the top of a respective one of the subsets. These portions are twisted together with respective portions of the return and bypass wires.
In such a U-Return embodiment, the bypass wire extends essentially directly across the set at a top thereof, but the return wire extends in a U-shape configuration along one vertically extending side, a bottom, and another vertically extending side of the set. The first pseudowire is twisted together with the active wire in each vertical string in each subset (except optionally a first vertical string of the first subset and a last vertical string of the last subset). The active wire of the first and last vertical strings is twisted together with portions of the return wire extending along the vertically extending sides of the set, and, alternately, portions of the active wire extending across at least one pair of adjacent vertical strings at the bottom of a respective one of the subsets and portions of the first pseudowire extending across at least one other pair of adjacent vertical strings at the bottom of a respective one of the subsets are twisted together with respective successive portions of the return wire.
The present invention further encompasses a net light set comprising a common wire means extending in a substantially horizontal first direction, the common wire means including lengths of a single bypass wire and a single return wire. A plurality of series-connected light strings extend physically parallel to each other and in a substantially vertical second direction transverse to the first direction, each light string including a plurality of lamp sockets and a plurality of intermediate lengths of a single active wire connecting the lamp sockets in series. In each of the light strings intermediate the first and last light strings, the single active wire is twisted together intermediate the lamp sockets only with a first non-wire extending in the second direction for enhanced tensile strength. At least one second non-wire extends in the first direction and physically connects intermediate lengths of each light string with corresponding intermediate lengths of other light strings. Plug means are disposed at one end of the light set and including the active and return wires. Adjacent each of the lamp sockets in each of the light strings, intermediate the first and last light strings and intermediate the top and bottom lamp sockets, the second non-wire extends in the first direction and crimps one of the socket-entering and socket-leaving single active wire portions about the other single active wire portion.
Preferably, the second non-wire extends to one side (e.g., the rear) of the socket-entering single active wire and the first non-wire twisted therewith, then to an opposite side (e.g., the front) of the socket-entering single active wire and the socket-leaving single active wire, and finally loops about the socket-entering single active wire before continuing intermediate the socket-entering single active wire and the socket-leaving single active wire in the first direction. Thus, the second non-wire blocks sliding movement of the lamp socket in both the first and second directions, thereby to provide the set with a net appearance.
In a preferred embodiment, spaced apart lengths of the first non-wire on opposite sides of a respective one of the lamp sockets are bridged by a third length of the first non-wire bypassing the respective one lamp socket. The set may additionally including means for commonly orienting the lamp sockets relative to one of the socket-entering and socket-leaving single active wires, the orienting means not functioning to block sliding movement of the lamp socket. Preferably, the first non-wire has a tensile strength of at least 28 lbs., although the second non-wire need not.